Elemental Symbols and Atomic Weights

The spreadsheet shown in Figure 9-1, containing a list of element symbols and atomic weights, is part of a one-way table (the table entries extend down to row 110). In a one-way table, the lookup values occupy a single row or column of the table (here, the lookup values are found in column B). 

Reading the periodic table takes a little practice. To begin with, each element has its own box with two key numbers. The atomic number of the element, or the number of protons its atoms contain, is at the top of the box. (See the table in the Appendix on pages 92-93.) Below the atomic number is the element s symbol letter or letters. The elements name is printed below the symbol, and underneath the name is the atomic weight. Element boxes on some periodic tables may include only the element symbol and atomic number. 

List of Elements with Their Symbols and Atomic Weights... 

A modem version of the periodic table, with the elements arranged by atomic number, is shown in Figure 2.15 (see also inside front covct). Each entry lists the atomic number, atomic symbol, and atomic weight of an element Ibis is a convaiiait way of tabulating such information, and you should become familiar with using the pmodic table for that purpose. As we develop the subject matt of chemistry throughout the text, you will see how useful the periodic table is. 

Hydrogen The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight 1. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are protons. Besides the common HI isotope, hydrogen exists as the stable isotope deuterium and the unstable, radioactive isotope tritium. [NIH]... 

H acid ORGCHEM H2NCioH4(OH)(S03H)2 a gray powder or crystalline substance that Is soluble in water, ether, and alcohol used as a dye Intermediate. ach as-od ) hafnium chem A metallic element, symbol Hf, atomic number 72, atomic weight 178.49 melting point 2000°C, boiling point above 5400°C. haf ne am )... 

In this reaction, a neutron is incident on a target atom with the elemental symbol T (atomic number Z and atomic weight A). The outgoing channel has a light and a heavy particle. The light particle, indicated by an elemental symbol r , is typically a proton, a deuteron, or an alpha particle, 2He". The heavy residual atom, denoted by the elemental symbol R, represents the target atom changed by whatever neutrons and/or protons that were transferred/picked up from the incident neutron. 

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